By the Blouin News Science & Health staff

New study shows complex fat-health relationship

by in Fitness & Wellbeing, Research.

An overweight woman sits on a chair in Times Square in New York on May 8, 2012

An overweight woman sits on a chair in Times Square (REUTERS/Lucas Jackson)

In a recent study published by the Journal of Clinical Endocrinology and Metabolism, Dr. Steven Smith, director of the Florida Hospital – Sanford-Burnham Translational Research Institute for Metabolism and Diabetes, and colleagues helped explain why belly fat is more likely to indicate a high risk of cardiac incident and diabetes than thigh or lower-body fat. Scientists are still not entirely sure why, but Dr. Smith’s discovery of genetic differences between belly fat and lower body fat is one of the first steps towards an answer. The homeobox genes differ in belly and lower body fat. These genes are involved in the regulation of patterns of anatomical development and respond to hormones and direct fat where to go. Therefore, belly and lower-body fat are pre-destined to go to certain parts of the body from the embryonic stage. Dr. Smith writes: “Even though many women hate having large hips and thighs, that pear shape actually reduces their risk of heart disease and diabetes.”

Other studies have shown that some fat, especially lower-body fat among women, is actually good for health. A 2010 Oxford University study showed that slow-burning hip fat makes more of the hormone adiponectin that protects the arteries and promotes better blood-sugar control. If this sounds counterintuitive, remember that fat itself is not the key issue here: Fat is necessary to protect nerves, as an energy source, as a storehouse for vitamins A, D, E and K, and to produce vital compounds such as steroids. Far more important to human health is body fat as a percentage of weight and the specific distribution of that fat. An August 2012 Mayo Clinic study  showed that people with a high waist-to-hip ratio and a normal BMI had a risk of cardiovascular death was 2.75 times higher than those in people with a low waist-to-hip ratio and a high BMI. Similarly, Dr. Paula Johnson, associate professor of medicine at Harvard Medical School, found belly fat is the most dangerous fat because it releases hormones and other substances that promote inflammation, raise blood pressure, alter cholesterol levels, and interfere with the normal function of blood vessels. In other words, it’s dangerous to carry a high amount of fat in your midsection.

Given the increasing problems that obesity presents worldwide, granular data like this is enormously important not just for personal and aesthetic reasons: it forms a crucial part of a necessary public-health discipline. Here’s hoping there are more studies like Dr. Smith’s in the pipeline.